368 On Aquatic Carnivorous Cokoptera or Dyiiscidce. 



short impressed stria at the base of the elytra. It varies a little in colour and size, 

 some individuals haviug the hind body and breast infuscate. The length of the striga 

 also varies a little, it is sometimes so abbreviated as to be scarcely perceptible. 



Atlantic States of North America: "from Lake Superior to Florida," Crotch. 131. 



321. Hydroporus pullus, Lee, M.C. — Elongato-ovaUs, nitidulus, tenuissime 

 pubescens, testaceus, elytris vittis elongatis fuscis tribus, crebre distincte punctatis ; 

 coxis posterioribus pectoreque impunctatis, nitidis. Long. 2, lat. 1 m.m. 



In this species the apical ventral segment is a good deal broader and larger than 

 in its allies, and by this character it may readily be distinguished from varieties of 

 other North American species which resemble it in appearance : it has moreover 

 an indistinct dorsal stria extending about half the length of the wing-case. The 

 tarsi are rather long and slender, but I see no differences between the sexes. 



North America, (Red River, Pennsylvania, Louisiana). 134. 



322. Hydroporus granarius, Aube, M.C. — Breviter ovalis, latus, subtus convexus,. 

 subtiliter pubescens, nitidus, ferrugineus, elytris obscurioribus ; prothorace obsolete 

 punctato, elytris crebre distincte punctatis ; coxis posterioribus nitidis, sparsim, 

 subtiliter sed distincte punctatis ; abdomine fere impunctato ; antennis fuscis, basi 

 testaceo. Long, if, lat. ll m.m. 



This species has the form of a minute Hyphydrus, the elytra continuing the 

 outline with the thorax. I see no sexual characters among the five specimens I 

 have examined, all of which have the tarsi small and rather slender. 



United States of North America, (Massachusetts). 140. 



323. Bidessus lynceus, n. sp. — Brevis, ovalis, fere sine pubescentia, nigricans, 

 capite fusco, prothorace ad angulos anteriores late testaceo, elytris fasciis duabus, 

 transversis, flaminulatis, testaceis ; prothorace basi et disco punctatis ; elytris^ 

 crebrius sat fortiter, pectore fortiter, punctatis ; antennis testaceis, apicem versus 

 plus minusve infuscatis. Long. 2, lat. ll m.m. 



The male has the upper surface a little shining, the anterior and middle tarsi 

 are but little dilated : in the female the upper surface is dull. 



The species is allied to Hydroporus cinctellus, Lee. (No. 255) but it is a good 

 deal broader and shorter, and the fasciae on the elytra are very irregular, being 

 irregularly angulate ; these yellow marks are variable in their extent, sometimes 

 occupying nearly half the surface of the wing-cases, and at other times diminished 

 in size, and broken into more or less separated marks. 



Central America, (Guatemala City, E. C. Champion). 1129. 



